Spark plug



H. W. SECRIST Aug. 5, 1952 SPARK PLUG Filed Nov. 50, 1948 INVENTOR. 4 #ar/61% Sec/*[52* ATTU R N EYS Patented Aug. 5, 1952 SPARK PLUG v Harley W. Secrst, Newark, Ohio. .application November 30, 1948, Serial No.-62,651`

2 Claims. (Ci. 7123469) This invention relates to improvements in spark i plugs. I V

Theobject of the invention is to provide a novel typ of spark plug.

Another object of the invention is to provide a spark plug having an electrode which is highly resis'tant to deterioration due to electrical in fluences with high temperatures.

A further object of the invention is to provide a spark plug which is' extremely simple and in" expensive to manufacture.

Other objects and advantages will -be apparent during the course of the following description.

In the accompanying drawings forming a part of this application, and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is a top plan view of the spark plug, according to the present invention;

Figure 2 is an enlarged sectional View taken on the line 2-2 of Figure 1;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2.

Refering in dete-il to the drawings, the spark plug comprises an insulator Hi fabricated of porcelain. The insulator is provided with a bore ll extending from one of the ends thereof, and extending from the other end of the insulator is an enlarged recess !2 which communicates with the bore H. Positioned within the bore I I is a tubular jacket !3 fabricated of tungsten steel, and a disk-shaped end of the jacket |3 abuts an end of a tubular cooling chamber M which is arranged in the recess !2.

Extending through the jacket (3 and through the cooling chamber Hi is an elongated center electrocle !5 fabricated of copper. The electrode l5 is abricated of copper which has been heat treated, as in a furnace, and the electrode !5 is welded to the steel jacket [3 so that there will be no loss of compression therebetween. The cooling chamber M is provided with an enlarged sockct IB which surrounds a portion of the electrode !5 to provide a cooling means for the latter. The cooling ehamber !4 is provided with a plurality of radially-disposed apertures or openings IT for the passage therethrough of air to and from the interier of the cooling Cham-ber The upper end of the cooling chamber !4 is threaded exteriorly, as at !8, and threaded thereon is a suitable terminal Connector !9.

The insulation lil is mounted in the usual shell, indicated at 2%), and the shell is fabricated of metal screw stock: A bushing 2| surrounds the insulator o and is in threaded engagement with a portion of the shell 20 for maintainingtheparts in assembled relation. A pair of'gaskets 22. and 23 fabricated of copper'are interposed'between the shell 20 and the insulator Ifl `for provicling a fluid-tight connection.

The lower portion of the shell 20 isthreaded v exteriorly, as at 24, for engagement with the engine housing and dependingly carried by the bottom of the shell 20 is a sparking point 25 which is fabricated of tungsten alloy.

From the foregoing, it will be apparent that a spark plug has been provided which includes a single copper electrode !5 that extends com.- pletely therethrough. This electrode provides an excellent conductor for electrical energy. The steel jacket serves to protect the ele'ctrode !5 against deterioration or corrosion caused by heat and electrical influences under high temperatures.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

1. In a spark plug, an insulator fabricated of porelain provided with a bore extending therethrough for a portion of its length, there being a recess extending from the other end of said insulator and communicating with said bore, a tubular jacket fabricated of tungsten steel positioned within said bore, a disk shaped end on said jacket within said recess; a cooling chamber seated on said disk shaped end in said recess, there being a plurality of radially-disposed apertures in said cha'rnber for the passage therethrough of air, an electrode'fabricated of copper extending through said cooling chamber and jacket, a shell arranged in embracing relation with respect to the lower portion of said insulator and operatively connected to the latter, and a spark plug point dependingly carried by said shell, said spark plug point being fabricated of a tungsten alloy, said spark plug point having an L-shape, the inner surface of said cooling chamber being spaced from the outer surface of said electrode, the lower portion of said insulator extending below said shell, and the jacket extending below said insulator for a distance equal to the exposed end of the electrode.

2. In a spark plug, an insulator fabricated of porcelain and provided with a bore extending therethrough for a portion of its length, there being a recess extending through a portion of said insulator and communicating with said bore, said recess being of a greater diameter than said bore, a tubular jacket fabricated of tungsten steel positioned within said bore and having a disk like portion projecting beyond the latter, a cooling chamber projecting longitudinally through said recess and having o-ne end abutting the disk like portion of said jacket, said coolin chamber' having a portion projecting beyond said insulator, said projecting portion of said cooling chamber being provided with a plurality of radially disposed apertures for the passage therethrough of air and external threads above said apertures to receive a terminal connection, an electrode fabricated of copper extending through said cooling chamber and jacket and the projected portion of the cooling chamber and rigidly fixed to said jacket, a, shell arranged in 'embracing relation with respect to the lower portion of said insulator and operatively connected to the Jatter, and a spark plug point dependingiy carried by said shell, said spark plug point being fabrica'ted of a tungsten alloy, said spark plug point having an L-shape, the inner surface of said cooling chamber being spaced from the outer surface of said electrode, the lower portion of said insulator extending below said shell, and the jacket extendng below said insulator for a distance equal to the exposed end of the electrode.

I-IARLEY W. SECRIST.

REFERENCES oIT D The following references 'are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,315,298 Genn Sept. 9, 1919 1,471,283 Rogers Oct. 16, 1923 1,762,989 Hurley June 10, 1930 1,842,833 Leonard Jan. 26, 1932 1,842334 Leonard Jan. 26, 1932 2,081,501 Nowosielski May 25, 1937 FORE'IGN PATENTS Number Country Date 514273 France Mar. 7, 1921 

